Good luck with that. I have pretty much determined that there is no "good" in the end of a relationship with an addict. There is "good" after the end. Unfortunately addicts have to make the leaving part as difficult and horrible as possible when a relationship is over. They don't just go away peacefully. I wish they did.
My ex showed up to visit his son and refuses to leave. And he's a jerk. And I keep asking him to leave. But he doesn't go. So now I will have to have a scene. It just sucks. He's just not normal. Who shows up for child visitation and then NEVER leaves? He won't even get up off the couch for fear he won't be able to lay back down on it. I set boundaries and dates and he just ignores them. It's psychotic! Who wants to live somewhere they are not wanted? He does. And he's not even using. But he's sick and screwed up. He just doesn't get it.
And yes. You do have to serve them with a notice to evict because they aren't like normal people. They don't leave when asked. So you have to bring the courts in. It's all a bunch of bull-pucky.